For our navigation on Curacao, we used the Android App: OsmAnd. You can download the map from Curacao and use navigation in offline mode. It was very good and freeware and helped us, to navigate in and around Willemstad.

If you travel to Curacao and you are allergic on mosquitoes (there are many mosquitoes) – you must buy this! You can buy it in every supermarket. http://www.amazon.de/CARE-PLUS-Deet-Insect-Lotion/dp/B000K25Q5W